English
Related papers

Related papers: Deformation of Dirac operators along orbits and qu…

200 papers

We consider a invariant Dirac operator D on a manifold with a proper and cocompact action of a discrete group G. It gives rise to an equivariant K-homology class [D]. We show how the index of the induced orbifold Dirac operator can be…

K-Theory and Homology · Mathematics 2007-05-23 Ulrich Bunke

We study two special cases of the equivariant index defined in part I of this series. We apply this index to deformations of Spin$^c$-Dirac operators, invariant under actions by possibly noncompact groups, with possibly noncompact orbit…

Differential Geometry · Mathematics 2016-03-11 Peter Hochs , Yanli Song

In an earlier article we introduced a new definition for the `quantization' of a Hamiltonian loop group space $\mathcal{M}$, involving the equivariant $L^2$-index of a Dirac-type operator $\mathscr{D}$ on a non-compact finite dimensional…

Symplectic Geometry · Mathematics 2019-12-02 Yiannis Loizides , Yanli Song

Let $D$ be a (generalized) Dirac operator on a non-compact complete Riemannian manifold $M$ acted on by a compact Lie group $G$. Let $v:M --> Lie(G)$ be an equivariant map, such that the corresponding vector field on $M$ does not vanish…

Mathematical Physics · Physics 2007-05-23 Maxim Braverman

In this paper we construct an explicit quasi-isomorphism to study the cyclic cohomology of a deformation quantization over a riemannian \'etale groupoid. Such a quasi-isomorphism allows us to propose a general algebraic index problem for…

Quantum Algebra · Mathematics 2015-05-13 M. J. Pflaum , H. Posthuma , X. Tang

In the first part of this series, we defined an equivariant index without assuming the group acting or the orbit space of the action to be compact. This allowed us to generalise an index of deformed Dirac operators, defined for compact…

K-Theory and Homology · Mathematics 2016-02-10 Peter Hochs , Yanli Song

We provide geometric quantization of a completely integrable Hamiltonian system in the action-angle variables around an invariant torus with respect to polarization spanned by almost-Hamiltonian vector fields of angle variables. The…

Quantum Physics · Physics 2015-06-26 G. Giachetta , L. Mangiarotti , G. Sardanashvily

Consider the compact quantum group $U_q(2)$, where $q$ is a non-zero complex deformation parameter such that $|q|\neq 1$. Let $C(U_q(2))$ denote the underlying $C^*$-algebra of the compact quantum group $U_q(2)$. We prove that if $q$ is a…

Operator Algebras · Mathematics 2026-04-22 Debabrata Jana

We give a framework of localization for the index of a Dirac-type operator on an open manifold. Suppose the open manifold has a compact subset whose complement is covered by a family of finitely many open subsets, each of which has a…

Differential Geometry · Mathematics 2015-03-13 Hajime Fujita , Mikio Furuta , Takahiko Yoshida

Suppose that $(M,E)$ is a compact contact manifold, and that a compact Lie group $G$ acts on $M$ transverse to the contact distribution $E$. In an earlier paper, we defined a $G$-transversally elliptic Dirac operator $\dirac$, constructed…

Symplectic Geometry · Mathematics 2012-01-17 Sean Fitzpatrick

We define an equivariant index of Spin$^c$-Dirac operators on possibly noncompact manifolds, acted on by compact, connected Lie groups. The main result in this paper is that the index decomposes into irreducible representations according to…

Differential Geometry · Mathematics 2017-10-18 Peter Hochs , Yanli Song

We study the index theory of a class of perturbed Dirac operators on non-compact manifolds of the form $\mathsf{D}+\mathrm{i}\mathsf{c}(X)$, where $\mathsf{c}(X)$ is a Clifford multiplication operator by an orbital vector field with respect…

K-Theory and Homology · Mathematics 2021-01-15 Yiannis Loizides , Rudy Rodsphon , Yanli Song

We factorize the Dirac operator on the Connes-Landi 4-sphere in unbounded KK-theory. We show that a family of Dirac operators along the orbits of the torus action defines an unbounded Kasparov module, while the Dirac operator on the…

Operator Algebras · Mathematics 2019-08-28 Jens Kaad , Walter D. van Suijlekom

We define an $S^1$-equivariant index for non-compact symplectic manifolds with Hamiltonian $S^1$-action. We use the perturbation by Dirac-type operator along the $S^1$-orbits. We give a formulation and a proof of quantization conjecture for…

Symplectic Geometry · Mathematics 2018-01-12 Hajime Fujita

We show that the computation of the Fredholm index of a fully elliptic pseudodifferential operator on an integrated Lie manifold can be reduced to the computation of the index of a Dirac operator, perturbed by a smoothing operator,…

K-Theory and Homology · Mathematics 2022-04-20 Karsten Bohlen , Jean-Marie Lescure

We study various topological invariants on a torsional geometry in the presence of a totally anti-symmetric torsion H under the closed condition dH = 0, which appears in string theory compactification scenarios. By using the identification…

High Energy Physics - Theory · Physics 2008-11-26 Tetsuji Kimura

By a result of Nagy, the C*-algebra of continuous functions on the q-deformation G_q of a simply connected semisimple compact Lie group G is KK-equivalent to C(G). We show that under this equivalence the K-homology class of the Dirac…

Operator Algebras · Mathematics 2011-02-02 Sergey Neshveyev , Lars Tuset

We prove a Fredholm property for spin-c Dirac operators $\mathsf{D}$ on non-compact manifolds satisfying a certain condition with respect to the action of a semi-direct product group $K\ltimes \Gamma$, with $K$ compact and $\Gamma$…

K-Theory and Homology · Mathematics 2018-10-05 Yiannis Loizides , Yanli Song

This paper is the third of the series concerning the localization of the index of Dirac-type operators. In our previous papers we gave a formulation of index of Dirac-type operators on open manifolds under some geometric setting, whose…

Differential Geometry · Mathematics 2014-07-18 Hajime Fujita , Mikio Furuta , Takahiko Yoshida

We construct the coarse index class with support condition (as an element of coarse $K$-homology) of an equivariant Dirac operator on a complete Riemannian manifold endowed with a proper, isometric action of a group. We further show a…

Differential Geometry · Mathematics 2025-05-14 Ulrich Bunke , Alexander Engel
‹ Prev 1 2 3 10 Next ›